Synastry Calculator
Synastry overlays two birth charts and reads the angles between them, the aspects. Enter two birthdays and see exactly where your planets touch.
What your chart says about who fits you, your timing windows, and your love blocks. Free quiz, 60 seconds.
Start my free readingHow to read your aspects
Synastry aspects are specific angles between one person's planet and the other's. Conjunctions (0\u00b0) merge two energies, trines (120\u00b0) and sextiles (60\u00b0) flow easily, squares (90\u00b0) and oppositions (180\u00b0) create friction, which often reads as chemistry early and work later. The classics to look for: Sun-Moon contacts (the marriage aspect), Venus-Mars (raw attraction), and Moon-Moon (emotional home).
What this calculator includes
We compute Sun, Moon, Mercury, Venus, and Mars for both charts from real planetary positions and check every cross-pairing. Without birth times, Moon aspects use noon positions, the Moon moves ~13\u00b0 a day, so add times if you have them. New to this? Start with synastry for beginners.